Solid-state imaging device, production method, and electronic apparatus

ABSTRACT

The present technology relates to a solid-state imaging device, a production method, and an electronic apparatus that can prevent sensitivity unevenness from generating. The solid-state imaging device includes a pixel array unit having a plurality of pixels, a microlens formed by laminating a plurality of lens layers for the every pixel, and a film formed between the lens layers with a uniform film thickness having a refractive index lower than a refractive index of the lens layer. The present technology is applicable to an amplification type solid-state imaging device such as a surface irradiation type or rear irradiation type CMOS image sensor, and a charge transfer type solid-state imaging device such as a CCD image sensor.

TECHNICAL FIELD

The present technology relates to a solid-state imaging device, aproduction method, and an electronic apparatus, and in particularly to asolid-state imaging device, a production method, and an electronicapparatus that prevent sensitivity unevenness from generating.

BACKGROUND ART

In a solid-state imaging device in the related art, there is known amicrolens formed by a plurality of lens layers in order to optimize acurvature and a refractive index of a microlens in each pixel (seePatent Document 1, for example).

Patent Document 1: Japanese Patent Application Laid-open No. 2013-77740

SUMMARY Problem to be Solved

However, in the solid-state imaging device described in Patent Document1, an oxide film may be formed between lens layers by a process of amicrolens formation. The oxide film is not formed uniformly between thelens layers, and may be formed or not depending on places. Accordingly,sensitivity unevenness may be generated in whole pixels.

The present technology is made in view of the circumstances, andprevents sensitivity unevenness from generating.

Means for Solving the Problem

A solid-state imaging device according to an aspect of the presenttechnology includes a pixel array unit having a plurality of pixels; amicrolens formed by laminating a plurality of lens layers for the everypixel; and a film having a uniform film thickness formed between thelens layers.

The film may be an oxide film.

The film may have a refractive index lower than a refractive index ofthe lens layer.

The lens layer may be formed of an inorganic material.

The lens layer may be formed of SiN.

Among the plurality of lens layers, a lower layer, i.e., a first lenslayer may be formed of SiN, and an upper layer, i.e., a second lenslayer may be formed of SiON.

Among the plurality of lens layers, a lower layer, i.e., a first lenslayer may be formed of an inorganic material, and an upper layer, i.e.,a second lens layer may be formed of an organic material.

A method of producing a solid-state imaging device including a pixelarray unit having a plurality of pixels according to an aspect of thepresent technology includes the steps of: forming a microlens bylaminating a plurality of lens layers for the every pixel; and forming afilm having a uniform film thickness between the lens layers.

An electronic apparatus according to an aspect of the present technologyincludes a solid-state imaging device including a pixel array unithaving a plurality of pixels; a microlens formed by laminating aplurality of lens layers for the every pixel; and a film having auniform film thickness formed between the lens layers.

According to an aspect of the present technology, a microlens is formedby laminating a plurality of lens layers for every pixel, and a filmhaving a uniform film thickness is formed between lens layers.

Effects

According to an aspect of the present technology, it is possible toprevent sensitivity unevenness from generating.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a configuration example of asolid-state imaging device to which the present technology is applied.

FIG. 2 is a view for illustrating an oxide film formed in a solid-stateimaging device in the related art.

FIG. 3 are views for illustrating light-concentrating points insolid-state imaging devices in the related art.

FIG. 4 is a cross-sectional view showing a configuration example ofpixels according to a first embodiment of the present technology.

FIG. 5 is a view for illustrating a light-concentrating point in asolid-state imaging device according to the present technology.

FIG. 6 is a flowchart for illustrating pixel formation processing.

FIG. 7 are views for illustrating a process of pixel formation.

FIG. 8 are views for illustrating a process of pixel formation.

FIG. 9 is a cross-sectional view showing a configuration example ofpixels according to a second embodiment of the present technology.

FIG. 10 is a cross-sectional view showing a configuration example ofpixels according to a third embodiment of the present technology.

FIG. 11 is a cross-sectional view showing a configuration example ofpixels according to a fourth embodiment of the present technology.

FIG. 12 is a block diagram showing a configuration example of anelectronic apparatus to which the present technology is applied.

DESCRIPTION OF PREFERRED EMBODIMENTS

Hereinafter, the embodiments of the present technology will be describedreferring to drawings.

Configuration Example of Solid-State Imaging Device

FIG. 1 a block diagram showing a configuration which the presenttechnology is applied. Hereinafter, a configuration of a surfaceirradiation type CMOS (Complementary Metal Oxide Semiconductor) imagesensor that is one of amplification type solid-state imaging deviceswill be described. The present technology is not limited to be appliedto the surface irradiation type CMOS image sensor, and is applicable toa rear irradiation type CMOS image sensor, other amplification typesolid-state imaging device, and a charge transfer type solid-stateimaging device such as a CCD (Charge Coupled Device) image sensor.

A CMOS image sensor 10 shown in FIG. 1 has a configuration that includesa pixel array unit 11 formed on a semiconductor substrate (not shown),and peripheral circuit units integrated on the same semiconductorsubstrate of the pixel array unit 11. The peripheral circuit units areconfigured of, for example, a vertical driving unit 12, a columnprocessing unit 13, a horizontal driving unit 14, and a system controlunit 15.

Furthermore, the CMOS image sensor 10 includes a signal processing unit18 and a data storing unit 19.

The pixel array unit 11 includes a plurality of unit pixels thatgenerate light electrical charge corresponding to a received lightamount and have photoelectric conversion units for accumulation(hereinafter referred to simply as pixels). Specifically, the pixelarray unit 11 has a configuration that the pixels are two-dimensionallyarranged in a row direction and a column direction, i.e., in a matrix.Here, the row direction represents an arrangement direction (horizontaldirection) of pixels in a pixel row, and the column direction representsan arrangement direction (vertical direction) of pixels in a pixelcolumn.

In the matrix pixel arrangement of the pixel array unit 11, a pixeldriving line 16 is wired along the row direction for every pixel row,and a vertical signal line 17 is wired along the column direction forevery pixel column. The pixel driving line 16 transmits a driving signalfor driving when a signal is read-out from the pixel. In FIG. 1, thepixel driving line 16 is shown in one wire, but is not limited to one.One end of the pixel driving line 16 is connected to an output endcorresponding to each column of the vertical driving unit 12.

The vertical driving unit 12 is configured of a shift resistor and anaddress decoder, and drives each pixel of the pixel array unit 11 at thesame time or in a row unit. In other words, the vertical driving unit 12configures a driving unit that drives each pixel of the pixel array unit11 together with the system control unit 15 that controls the verticaldriving unit 12. The vertical driving unit 12 typically has two scanningsystems of a read-out scanning system and a sweep scanning system,although specific configuration thereof is not shown.

The read-out scanning system selectively scans a unit pixel of the pixelarray unit 11 in a row unit in order to read-out a signal from the unitpixel. The signal read out from the unit pixel is an analog signal. Thesweep scanning system sweep-scans before the read-out scanning by ashutter speed time period for a read-out row that is read-out scanned bythe read-out scanning system.

As the sweep scanning system sweep-scans to sweep unnecessary chargesfrom photoelectric conversion units of the unit pixel in the read-outrow. By sweeping (resetting) the unnecessary charges by the sweepscanning system, an electronic shutter operation is performed. Here, theelectronic shutter operation refers to an operation that lightelectrical charge in the photoelectric conversion units are discarded,and exposure is newly started (accumulation of the light electricalcharge is started).

The signal read out by a read-out operation of the read-out scanningsystem corresponds to a received light amount directly before theread-out operation or after the electronic shutter operation. Then, aperiod from a read-out timing by the read-out operation directly beforeor a sweep-out timing by the electronic shutter to a read-out timing bythe read-out operation this time is an exposure period of lightelectrical charge in the unit pixel.

A signal output from each unit pixel in the pixel row selectivelyscanned by the vertical driving unit 12 is input to the columnprocessing unit 13 through each of the vertical signal lines 17 forevery pixel column. The column processing unit 13 performs predeterminedsignal processing to a signal output through the vertical signal line 17from each pixel in a selected row for every pixel column of the pixelarray unit 11, and holds temporarily the pixel signal after the signalprocessing.

Specifically, the column processing unit 13 performs, as the signalprocessing, at least noise removal processing, for example, CDS(Correlated Double Sampling) processing. Through the CDS processing bythe column processing unit 13, a fixed pattern noise specific to thepixel such as reset noise and a threshold value variation of anamplifying transistor within the pixel is removed. The column processingunit 13 may have an AD (Analog-Digital) converting function other thanthe noise removal processing, whereby an analog pixel signal may beconverted into a digital signal to be output.

The horizontal driving unit 14 is configured of a shift resistor, anaddress decoder, or the like, and sequentially selects the unit circuitcorresponding to the pixel column of the column processing unit 13.Through the selective scanning by the horizontal driving unit 14, thepixel signal that is subjected to the signal processing for every unitcircuit in the column processing unit 13 is sequentially output.

The system control unit 15 is configured of a timing generator thatgenerates a variety of timing signals. On the basis of a variety oftiming signals generated by the timing generator, the system controlunit 15 performs a driving control of the vertical driving unit 12, thecolumn processing unit 13, the horizontal driving unit 14 and the like.

The signal processing unit 18 has at least an arithmetic processingfunction, and performs a variety of signal processing such as arithmeticprocessing to the pixel signal output from the column processing unit13. The data storing unit 19 temporarily stores data necessary for thesignal processing at the signal processing unit 18.

The signal processing unit 18 and the data storing unit 19 may bemounted on the same substrate (semiconductor substrate) of the CMOSimage sensor 10, or may be mounted on a separate substrate from the CMOSimage sensor 10. In addition, each processing by the signal processingunit 18 and the data storing unit 19 may be executed as the processingby an external signal processing unit mounted on a separate substratefrom the CMOS image sensor 10, for example, a DSP (Digital SignalProcessor) circuit or software.

Furthermore, when the CMOS image sensor 10 is a rear irradiation typeCMOS image sensor, the CMOS image sensor 10 may be configured as alamination type CMOS image sensor where the semiconductor substrateincluding the pixel array unit 11 is adhered to the semiconductorsubstrate including the logic circuit.

Solid-State Imaging Device in Related Art

In the related art, a microlens is formed by laminating a plurality oflens layers in the solid-state imaging device in order to optimize acurvature and a refractive index of a microlens in each pixel.

FIG. 2 is a cross-sectional view showing a configuration example ofpixels in a solid-state imaging device in the related art includingmicrolenses formed by laminating a plurality of lens layers.

As shown in FIG. 2, a photoelectric conversion unit 52 that receivesincident light and performs photoelectric conversion is formed on asemiconductor substrate 51 in a pixel 31, and a wiring layer 53 isformed on an upper layer of the semiconductor substrate 51.

Above the wiring layer 53, a color filter layer 54 having spectralcharacteristics corresponding to each pixel 31 is formed for the everypixel 31, and microlenses 57 are formed over the color filter layer 54by laminating a first lens layer 55 and a second lens layer 56.

Furthermore, in the solid-state imaging device shown in FIG. 2, an oxidefilm 58 is formed between the first lens layer 55 and the second lenslayer 56 by a microlens formation process. The oxide film 58 is notuniformly formed between the first lens layer 55 and the second lenslayer 56, and may be formed or not depending on places. Accordingly,sensitivity unevenness may be generated in whole pixels.

Also, in the related art, when a light-concentrating point of theincident light from the microlens 57 is above a light receiving surfaceof the photoelectric conversion unit 52 (so-called front focus state) inthe solid-state imaging device, as shown in a left view of FIG. 3, theheight of the microlens 57 can be typically reduced.

However, when the height of the microlens 57 is tried to be reduced, apart of the color filter layer 54 may be scraped at parts where themicrolenses 57 of the respective pixels are adjacent by the first lenslayer 55 during etching upon the formation of the first lens layer 55.That is to say, in the solid-state imaging device including themicrolenses formed by laminating the plurality of lens layers, when itfalls into the front focus state, it is difficult to match thelight-concentrating point with the light receiving surface of thephotoelectric conversion unit 52.

Then, it describes below that the light-concentrating point can bematched with the light receiving surface of the photoelectric conversionunit 52 even when it falls into the front focus state, while it preventssensitivity unevenness from generating in whole pixels.

Configuration Example of Pixels According to First Embodiment

FIG. 4 is a cross-sectional view showing a configuration example ofpixels in the CMOS image sensor 10 according to a first embodiment.

As shown in FIG. 4, in pixels 131, photoelectric conversion units 152that receive incident light and perform photoelectric conversion areformed on a semiconductor substrate 151, and a wiring layer 153including Cu and Al is formed on upper layer of the semiconductorsubstrate 151.

Over the wiring layer 153, a color filter layer 154 having spectralcharacteristics corresponding to each pixel 131 is formed for the everypixel 131, and microlenses 157 are formed over the color filter layer154 by laminating a first lens layer 155 and a second lens layer 156.

The first lens layer 155 and the second lens layer 156 are formed of aninorganic material. Specifically, the first lens layer 155 and thesecond lens layer 156 are formed of SiN.

Between the first lens layer 155 and the second lens layer 156, an oxidefilm 158 having a uniform film thickness is formed. The oxide film 158has a refractive index lower than refractive indexes of the first lenslayer 155 and the second lens layer 156.

According to the configuration of this embodiment, in the solid-stateimaging device including the microlenses formed by laminating theplurality of lens layers, the oxide film 158 having a uniform filmthickness is intentionally formed between the lens layers, it ispossible to prevent the sensitivity unevenness from generating in wholepixels.

By setting the refractive index of the oxide film 158 to lower than therefractive index of the lens layer, as shown in FIG. 5, thelight-concentrating point of the incident light from the microlens 157can be decreased. In this manner, it is possible to match thelight-concentrating point with the light receiving surface of thephotoelectric conversion unit 152 even when it falls into the frontfocus state.

Flow of Pixel Formation

Next, referring to FIG. 6 to FIG. 8, a flow of the pixel formationaccording to this embodiment will be described. FIG. 6 is a flowchartfor illustrating the pixel formation processing, and FIG. 7 and FIG. 8are cross-sectional views for showing a process of the pixel formation.

Hereinafter, processing after the color filter layer 154 is formed willbe described.

In Step S11, as shown in “A” of FIG. 7, a lens material 155 a includingSiN is formed on the color filter layer 154.

In Step S12, as shown in “B” of FIG. 7, a resist pattern 161 is formedfor every pixel on the lens material 155 a by a photolithography method.

In Step S13, the resist pattern 161 is etched transfer to the lensmaterial 155 a to perform dry etching. In this manner, as shown in “C”of FIG. 7, the first lens layer 155 having lens shapes for respectivepixels is formed.

In Step S14, as shown in “D” of FIG. 8, the oxide film 158 having auniform film thickness is formed on the first lens layer 155 formed forthe respective pixels. Specifically, an oxide film is grown on thesurface of the first lens layer 155 using oxygen plasma to form theoxide film 158. Other than using oxygen plasma, a CVD (Chemical VaporDeposition) method or a sputtering method may be used to form the oxidefilm 158.

In Step S15, as shown in “E” in FIG. 8, the lens material 156 aincluding SiN is formed on the oxide film 158. The lens material 156 ais formed along the lens shapes of the first lens layer 155 and theoxide film 158.

In Step S16, the lens material 156 a is dry etched to form the secondlens layer 156, as shown in “F” of FIG. 8. In this manner, themicrolenses 157 where the first lens layer 155 and the second lens layer156 are laminated for respective capturing pixels 131 are formed.

In this manner, the pixels 131 are formed.

By the above-described processing, in the production process of thesolid-state imaging device including the plurality of lens where thelayers are laminated and formed, the oxide film having a uniform filmthickness is intentionally formed between the lens layers, it ispossible to prevent the sensitivity unevenness from generating in wholepixels.

In the above, the microlens is formed by laminating two lens layers.Note that three or more of the lens layers may be laminated and formed.

Configuration Example of Pixels According to Second Embodiment

FIG. 9 shows a configuration example of pixels according to a secondembodiment.

The parts formed by the pixels 131 shown in FIG. 9 similar to thoseformed by the pixels 131 shown in FIG. 4 are omitted from thedescription.

As shown in FIG. 9, in the pixels 131, microlenses 172 are formed bylaminating the first lens layer 155, the second lens layer 156, and athird lens layer 171 for the respective pixels 131.

The third lens layer 171 is formed of SiN similar to the first lenslayer 155 and the second lens layer 156.

An oxide film 173 having a uniform film thickness is formed between thesecond lens layer 156 and the third lens layer 171 similar to the oxidefilm 158 formed between the first lens layer 155 and the second lenslayer 156. The oxide film 173 also has a refractive index lower than therefractive index of each of the first lens layer 155, the second lenslayer 156, and the third lens layer 171.

Also in this embodiment, in the solid-state imaging device including themicrolenses formed by laminating the plurality of lens layers, as theoxide films 158, 173 having a uniform film thickness are intentionallyformed between the lens layers, it is possible to prevent thesensitivity unevenness from generating in whole pixels.

Also, by setting the refractive index of the oxide film 158 to lowerthan the refractive index of the lens layer, as shown in FIG. 5, thelight-concentrating point of the incident light from the microlens 172can be decreased. In this manner, it is possible to match thelight-concentrating point with the light receiving surface of thephotoelectric conversion unit 152 even when it falls into the frontfocus state.

In the above, the microlens is formed by laminating three lens layers.Note that four or more of the lens layers may be laminated and formed.

As a flow of the pixel formation in this embodiment is basically similarto the flow of the pixel formation described referring to FIG. 6 to FIG.8 except that the processing in Steps S14 to S16 of the flowchart inFIG. 6 is repeated for the number of lens layers laminated, thedescription is omitted.

As above, the microlens is formed by laminating the plurality of lenslayers including the same material, but may be formed by laminating theplurality of lens layers including different materials.

Configuration Example of Pixels According to Third Embodiment

FIG. 10 shows a configuration example of pixels according to a thirdembodiment.

The parts formed by the pixels 131 shown in FIG. 10 similar to thoseformed by the pixels 131 shown in FIG. 4 are omitted from thedescription.

As shown in FIG. 10, in the pixels 131, the first lens layer 155 and thesecond lens layer 181 are laminated for the every pixel 131 to form amicrolens 182.

The second lens layer 181 is formed of an inorganic material differentfrom the first lens layer 155. Specifically, the second lens layer 181is formed of SiON having a refractive index difference between SiON andthe oxide film 158 being lower than that between SiN and the oxide film158.

According to this embodiment, the operation and effect are exertedsimilar to the above-described embodiments. In addition, as the secondlens layer 181 is formed of SiON having a refractive index differencebetween SiON and the oxide film 158 being lower than that between SiNand the oxide film 158, total reflection at a boundary between the oxidefilm 158 and the second lens layer 181 can be decreased, whereby it ispossible to prevent a sensitivity from decreasing.

In the above description, the microlens is formed by laminating two lenslayers. When the microlens is formed by laminating three or more lenslayers, all lens layers laminated on the upper layer of the oxide filmare formed of SiON, for example.

Configuration Example of Pixels According to Fourth Embodiment

FIG. 11 shows a configuration example of pixels according to a fourthembodiment.

The parts formed by the pixels 131 shown in FIG. 11 similar to thoseformed by the pixels 131 shown in FIG. 4 are omitted from thedescription.

As shown in FIG. 11, in the pixels 131, the first lens layer 155 and thesecond lens layer 191 are laminated for the every pixel 131 to form amicrolens 192.

The second lens layer 191 is formed of an organic material differentfrom the first lens layer 155.

According to this embodiment, the operation and effect are exertedsimilar to the above-described embodiments, too.

In the above description, the microlens is formed by laminating two lenslayers. When the microlens is formed by laminating three or more lenslayers, all lens layers laminated on the upper layer of the oxide filmare formed of an organic material, for example.

Configuration Example of Electronic Apparatus

Next, referring to FIG. 12, a configuration example of an electronicapparatus to which the present technology is applied will be described.

An electronic apparatus 500 shown in FIG. 12 includes an optical lens501, a shutter apparatus 502, a solid-state imaging device 503, adriving circuit 504, and a signal processing circuit 505. FIG. 12 showsthe configuration that the CMOS image sensor 10 having the pixels in theabove-described embodiment is disposed at an electronic apparatus (forexample, digital still camera) as the solid-state imaging device 503.

The optical lens 501 captures image light (incident light) from anobject to be imaged on an imaging surface of the solid-state imagingdevice 503. In this manner, a signal charge is accumulated for a certainperiod of time within the solid-state imaging device 503. The shutterapparatus 502 controls a light irradiation period and a light shieldperiod for the solid-state imaging device 503.

The driving circuit 504 supplies the driving signal that controls asignal transfer operation of the solid-state imaging device 503 and ashutter operation of the shutter apparatus 502. By the driving signal(timing signal) supplied from the driving circuit 504, the solid-stateimaging device 503 performs a signal transfer. The signal processingcircuit 505 performs a variety of signal processing to the signal outputfrom the solid-state imaging device 503. A video signal on which thesignal processing is performed is stored in a storage medium such as amemory or is output to a monitor.

Furthermore, the electronic apparatus 500 includes a lens driving unit(not shown) that drives the optical lens 501 in its light axisdirection. The lens driving unit configures a focus mechanism thatperforms a focus adjustment together with the optical lens 501. In theelectronic apparatus 500, a variety of controls such as a control of thefocus mechanism and a control of the above-described respectivecomponents are performed by a system controller (not shown).

In the electronic apparatus 500 according to the embodiment of thepresent technology, sensitivity unevenness can be prevented fromgenerating in the solid-state imaging device 503. As a result, an imagequality is improved.

The embodiments of the present technology are not limited to theabove-described embodiments, and any modification is possible withoutdeparting from the scope of the present technology.

The present technology may have the following configurations.

(1) A solid-state imaging device, including:

a pixel array unit having a plurality of pixels;

a microlens formed by laminating a plurality of lens layers for theevery pixel; and

a film having a uniform film thickness formed between the lens layers.

(2) The solid-state imaging device according to (1), in which

the film is an oxide film.

(3) The solid-state imaging device according to (1) or (2), in which

the film has a refractive index lower than a refractive index of thelens layer.

(4) The solid-state imaging device according to any one of (1) to (3),in which

the lens layer is formed of an inorganic material.

(5) The solid-state imaging device according to (4), in which

the lens layer is formed of SiN.

(6) The solid-state imaging device according to (4), in which

a lower layer that is a first lens layer among the plurality of lenslayers is formed of SiN, and an upper layer that is a second lens layeris formed of SiON.

(7) The solid-state imaging device according to any one of (1) to (3),in which

a lower layer that is a first lens layer among the plurality of lenslayers is formed of an inorganic material, and an upper layer that is asecond lens layer is formed of an organic material.

(8) A method of producing a solid-state imaging device including a pixelarray unit having a plurality of pixels, including the steps of:

forming a microlens by laminating a plurality of lens layers for theevery pixel; and

forming a film having a uniform film thickness.

(9) An electronic apparatus, including:a solid-state imaging device includinga pixel array unit having a plurality of pixels,a microlens formed by laminating a plurality of lens layers for theevery pixel, anda film having a uniform film thickness formed between the lens layers.

DESCRIPTION OF SYMBOLS

10 CMOS image sensor

11 pixel array unit

131 pixel

151 semiconductor substrate

152 photoelectric conversion unit

155 first lens layer

156 second lens layer

157 microlens

158 oxide film

500 electronic apparatus

503 solid-state imaging device

What is claimed is:
 1. A solid-state imaging device imaging device,comprising: a pixel array unit having a plurality of pixels; a microlensformed by laminating a plurality of lens layers for the every pixel; anda film having a uniform film thickness formed between the lens layers.2. The solid-state imaging device according to claim 1, wherein the filmis an oxide film.
 3. The solid-state imaging device according to claim2, wherein the film has a refractive index lower than a refractive indexof the lens layer.
 4. The solid-state imaging device according to claim3, wherein the lens layer is formed of an inorganic material.
 5. Thesolid-state imaging device according to claim 4, wherein the lens layeris formed of SiN.
 6. The solid-state imaging device according to claim4, wherein a lower layer that is a first lens layer among the pluralityof lens layers is formed of SiN, and an upper layer that is a secondlens layer is formed of SiON.
 7. The solid-state imaging deviceaccording to claim 3, wherein a lower layer that is a first lens layeramong the plurality of lens layers is formed of an inorganic material,and an upper layer that is a second lens layer is formed of an organicmaterial.
 8. A method of producing a solid-state imaging deviceincluding a pixel array unit having a plurality of pixels, comprisingthe steps of: forming a microlens by laminating a plurality of lenslayers for the every pixel; and forming a film having a uniform filmthickness.
 9. An electronic apparatus, comprising: a solid-state imagingdevice including a pixel array unit having a plurality of pixels, amicrolens formed by laminating a plurality of lens layers for the everypixel, and a film having a uniform film thickness formed between thelens layers.